The invention relates to a bioactive hydrogel, which can be used as biomaterial for replacing biological tissue, as an implant material or in the broadest sense in medicinal products.
“Biomaterial” means, in the sense of the invention, materials that are brought into contact with a biological organism in diagnostic or therapeutic applications. These materials must meet special requirements with respect to biocompatibility. “Biocompatibility” means the absence of clinically significant reactions of the organism to the use of materials, medicinal products or medical systems.
Bioactive hydrogels of this kind are used particularly advantageously as implant or tissue-replacement materials.
Various approaches for production of bioactive hydrogels are known in the prior art. Various implant or tissue-replacement materials have been investigated for use in regenerative therapies, for example for supporting the regeneration of blood vessels and nerve tracts or as skin replacement materials. For this, framework or carrier materials, so-called scaffolds, have been developed based on biological or synthetic main components, which after transplantation are intended temporarily to perform important functions of the natural extracellular matrix ECM. Cells in natural tissues exist within this ECM. The ECM is a complex, supramolecular network of various structural proteins, mainly collagen, proteoglycans, glycoproteins and elastin, whose structural organization and functional composition are essential for maintaining normal tissue architecture and for tissue-specific functions.
According to the current level of science, so-called scaffolds, which primarily perform a carrying and supporting function for the cells of importance for the regeneration processes and provide protection against mechanical stresses, are used for the aforementioned regenerative processes. For example, the use of highly hydrated materials, so-called hydrogels with synthetic or biological main components, which are degradable in the body over quite long periods without cell-damaging effects, is known from U.S. Pat. Nos. 6,306,922 A and 6,602,975.
So as to be able to support even complex multicellular processes, mixtures of components of the natural ECM or also materials for reversible binding and release of therapeutically relevant signal molecules have also been developed. For the last-mentioned functions, combinations of synthetic and polysaccharide-based components of the natural ECM have also been developed, which exploit the special affinity of these molecules for important signal molecules, for example growth factors.
A disadvantage of the materials known in the prior art is that the complex therapeutic problems of the known hydrogels are not solved sufficiently effectively in all respects. Moreover, most of the materials hitherto described are restricted to a narrow range in their physical properties, in particular in their mechanical properties, relating to stiffness and swelling, due to the limitations of crosslinking chemistry or the exclusive use of natural substances.